solving variables. . .solve for y?

Question

1. x-y=5; y= 2. 2x-y=7; y= 3. 4x+2y=6; y= 4. 18x+6y=12;y=
5. 6x-3y=-18;y= 6. 5y-5x=10 7. -7y-42x=7 8. 12x-4y=0 9.-x-3y=0 10. 9x+2y=0 11. 3x+4y=8 12. .5+12y=-12 13. 2x-5y=4 14. 3x-7y=2 15.x+2y=5 16.2x-3y=6 17.x-y+2=0 18.6x+3y-24=0

Answer 1

1. x-y=5; y= x - 5
Add y to each side x - y + y = 5 + y, becomes x = 5 + y. Subtract 5 from each side, x - 5 = 5 - 5 + y, becomes x - 5 = y

Solve the rest on your own

Answer 2

For one, NEVER set a variable to anything unless you know what it is supposed to be (don't just "set x to zero"). Otherwise, the way I do algebra is to think of moving things around. Like If I want to solve for y in y+5x=10, I'll just move the 5x to the right, and reverse the sign. So you come up with y=10-5x. If you want to solve for x in that equation, get x and everything attached to it on one side: 5x=10-y (I just moved y over and reversed the sign). The you simply divide by the number in front of x on the opposite side: x=(10-y)/5. I hope you know how to simplify something like (10-y)/5.

Answer 3

i'll show you one example

you have to set one of the variables equal to zeo...

13. 2x-5y=4....set x to 0

-5y=4 so y=-4/5

to elaborate on the answer above me what hes trying to say is that you get rid of one variable...like if
x-y=5 and
y=x-5 then....

x+(x-5)=5
2x -5=5
x=5

Answer 4

Dude do your own homework. Otherwise ask a teacher for help.

Answer 5

3 x + 2 y = -4 x + 2 y = -8 ---->>>>>> ( x + 2 y) * ( - a million ) = ( - 8 ) * ( - a million ) - x -2y = + 8 3 x + 2 y = -4 + - x - 2 y = 8 _______________________ 2 x = 4 ---- > x = 2 --->>> 3 x + 2 y = -4 ---> 3 * ( 2 ) + 2 y = -4 ---> 6 + 2 y = -4 --> 6 + 2 y = -4 ---> 2 y = -4 -6 ---> 2 y = -10 ---> y = -5

Answer 6

There is a pattern for each one. Figure it out.

Answer 7

Do you own damn homework.